Sionna Therapeutics Inc. (SION): Advancing cystic fibrosis combination to Phase 2

Sionna Therapeutics Inc. (SION) announced plans to advance its proprietary dual combination of NBD1 stabilizer SION-451 + SION-2222 into a Phase 2a proof-of-concept trial (AscenSION CF) in 1Q27, following a post-hoc analysis of the PreciSION CF Phase 2a study of SION-719, which did not meet its key activity endpoint as an add-on to standard-of-care Trikafta. The analysis suggested SION-719 was biologically active, but its treatment signal was likely confounded by (1) pharmacokinetic outliers, (2) reduced Trikafta exposure (~25%-30% average decline), and (3) complex drug-drug interactions. Supported by these findings, SION will instead evaluate the SION-451 + SION-2222 dual combination. Separately, to prioritize this program and extend its cash runway into 2H29, SION is implementing a 46% workforce reduction and other cost-saving measures. Goldman Sachs maintains an Early-Stage Biotech designation for SION and updated its model for the most recent 10Q and lower 3Q26+ OpEx per updated gu